Dyson vacuum cleaners. I've had mine for about 20 years, had to replace a part here and there, but it's just as strong as the day I got it. Probably the single best purchase I've ever made. A close second would be my Sonicare toothbrush.
Dyson is a marketing company that happens to make okay vacuums. Anyone who owns a Miele or SEBO vacuum would never go to a Dyson. Dyson vacuums never hold up to their high quality bagged competitors in almost any regard. Just my 2c. I used my family's Dyson before moving out and buying a canister SEBO and the difference is remarkable.
https://www.nytimes.com/wirecutter/blog/what-we-learned-from-vacuum-enthusiasts/